Iraqi Prime Minister Haidar al-Abadi has arrived in Tehran on his first visit to Iran since taking office.

Iraqi state television said Abadi arrived shortly before midnight on October 20 for talks with Iranian officials, including President Hassan Rohani, about the ongoing battle against Islamic State militants.

Abadi's office said the trip is part of his bid "to unite the efforts of the region and the world to help Iraq in its war against the terrorist group."

The visit also aims to strengthen cooperation between the two neighbors "in the fields of energy, and housing and construction," the statement said.

IS overran much of the country's Sunni Arab heartland in a lightning offensive in June.

Tehran is a key backer of the Shi'ite-led government in Baghdad.

According to senior Iraqi Kurdish officials, Tehran has deployed troops on the Iraqi side of the border in the Khanaqin area, northeast of Baghdad.